1. Field
An embodiment of the present invention relates to an electrode assembly and a secondary battery using the same, and more particularly, to an electrode assembly and a secondary battery using the same that are capable of simplifying a process and saving cost by modifying the form of an electrode tab of an outermost substrate among electrode plates.
2. Description of the Related Technology
As portable electronic apparatuses are being miniaturized and lightened, research has been conducted into secondary batteries in their use as driving power sources. As the decreasing weight and functionality of portable wireless device products, including cellular phones, notebook computers, personal digital assistants (PDAs), etc. progress, the importance of the secondary battery in its use as a driving power source for such products is remarkably emphasized.
Since the secondary battery can be repeatedly used through the repetition of charging and discharging, the secondary battery is more economical than a primary battery. Moreover, since the miniaturization and the high capacity of the secondary battery can be utilized, and the secondary battery has high operating voltage and high energy density per weight, the secondary battery is being widely used in high-tech electronic devices.
In particular, the lithium secondary battery, which typically has an operating voltage of 3.7V, is three times higher than the nickel-cadmium battery or the nickel-hydride battery which are primarily used as power sources for portable electronic equipments.
In general, the demand for certain secondary batteries, such as a can-type battery or a pouch-type battery having a small thickness that can be used with a cellular phone is high with respect to shape, and the demand for a secondary battery such as a lithium polymer battery having excellent energy density, discharge voltage, and safety is high with respect to material.
In the can-type or pouch-type battery, an electrode assembly, electrode tabs extending from the electrode assembly, and electrode leads welded to the electrode tabs are typically accommodated in a can or a pouch. The electrode assembly also typically has a structure in which an anode plate, a cathode plate, and a separator that is interposed therebetween and insulates them from each other are sequentially laminated or wound.
In addition, the electrode tabs typically are individually extended and fused from the anode plate and the cathode plate of the electrode assembly, and the electrode tabs typically are electrically connected with each of anode and cathode electrode leads and a part of each electrode tab is typically exposed outside the can or pouch. The exposed electrode lead is typically electrically connected with a protection circuit module in a subsequent process.
However, as such, the electrode tabs extending from each of the anode plate and the cathode plate of the electrode assembly are fused and thereafter, when each of the electrode tabs is connected with the electrode lead, the manufacturing process can become complicated and the electrode tab and the electrode lead may become separated from each other while the subsequent process is performed.